Lorenzo Gnoatto, Thomas Molier, Jelte J. Lamberts, Artim L. Bassant, Casper F. Schippers, Rembert A. Duine, Reinoud Lavrijsen
For magnonics and spintronics applications, the spin polarization (P) of a transport current and the magnetic damping (α) play a crucial role, e.g., for magnetization dynamics and magnetization switching applications. In particular, P in a glassy (amorphous) 3d transition ferromagnet such as CoFeB and α are both strongly affected by s−d scattering mechanisms. Hence, a correlation can be expected, which is a priori difficult to predict. In this work, P and α are measured using current-induced Doppler shifts using propagating spin wave spectroscopy and broadband ferromagnetic resonance techniques in blanket films and current-carrying CoxFe80−xB20 alloy microstrips. The measured P ranges from 0.18 ± 0.05 to 0.39 ± 0.05, and α ranges from (4.0 ± 0.2)·10−3 to (9.7 ± 0.6)·10−3. We find that for increasing P, a systematic drop in α is observed, indicating an interplay between magnetic damping and the spin polarization of the transport current, which suggests that interband scattering dominates in CoxFe80−xB20. Our results may guide future experiments, theory, and applications in advancing spintronics and metal magnonics.
{"title":"Investigating the interplay between spin polarization and magnetic damping in CoxFe80−xB20 for magnonics applications","authors":"Lorenzo Gnoatto, Thomas Molier, Jelte J. Lamberts, Artim L. Bassant, Casper F. Schippers, Rembert A. Duine, Reinoud Lavrijsen","doi":"10.1063/5.0254050","DOIUrl":"https://doi.org/10.1063/5.0254050","url":null,"abstract":"For magnonics and spintronics applications, the spin polarization (P) of a transport current and the magnetic damping (α) play a crucial role, e.g., for magnetization dynamics and magnetization switching applications. In particular, P in a glassy (amorphous) 3d transition ferromagnet such as CoFeB and α are both strongly affected by s−d scattering mechanisms. Hence, a correlation can be expected, which is a priori difficult to predict. In this work, P and α are measured using current-induced Doppler shifts using propagating spin wave spectroscopy and broadband ferromagnetic resonance techniques in blanket films and current-carrying CoxFe80−xB20 alloy microstrips. The measured P ranges from 0.18 ± 0.05 to 0.39 ± 0.05, and α ranges from (4.0 ± 0.2)·10−3 to (9.7 ± 0.6)·10−3. We find that for increasing P, a systematic drop in α is observed, indicating an interplay between magnetic damping and the spin polarization of the transport current, which suggests that interband scattering dominates in CoxFe80−xB20. Our results may guide future experiments, theory, and applications in advancing spintronics and metal magnonics.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"15 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143443911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Huimin Jiao, Jie Zhang, Tian Xing, Ruihua Zhao, Jianping Du
The electromagnetic wave pollution, originating from various electronic devices, has attracted widespread attention and has brought serious threats to human life. For this situation, the high-efficiency electromagnetic wave absorption (EMA) materials are required. Herein, carbon material modified with molybdenum dioxide is designed and synthesized by carbonizing the Mo-precursor. The Mo oxide/carbide-modified carbon materials are obtained by changing the raw material ratio and carbonized temperatures. The optimal material (MO-2-750) is composed of MoO2 and carbon with uniform nanotablet-like shapes and has excellent impedance matching. The maximum reflection loss of MO-2-750 is about −59.9 dB at a thickness of 2.2 mm, which is nearly 6 times that of carbon material. The effective absorption bandwidth is in the range of 11.29–17.32 GHz. This MoO2-modified carbon material could serve as an EMA platform in the electromagnetic wave absorption fields.
{"title":"MoO2-modified carbon nanotablets prepared by assembly of a polyoxomolybdate precursor for enhanced microwave absorption properties","authors":"Huimin Jiao, Jie Zhang, Tian Xing, Ruihua Zhao, Jianping Du","doi":"10.1063/5.0248212","DOIUrl":"https://doi.org/10.1063/5.0248212","url":null,"abstract":"The electromagnetic wave pollution, originating from various electronic devices, has attracted widespread attention and has brought serious threats to human life. For this situation, the high-efficiency electromagnetic wave absorption (EMA) materials are required. Herein, carbon material modified with molybdenum dioxide is designed and synthesized by carbonizing the Mo-precursor. The Mo oxide/carbide-modified carbon materials are obtained by changing the raw material ratio and carbonized temperatures. The optimal material (MO-2-750) is composed of MoO2 and carbon with uniform nanotablet-like shapes and has excellent impedance matching. The maximum reflection loss of MO-2-750 is about −59.9 dB at a thickness of 2.2 mm, which is nearly 6 times that of carbon material. The effective absorption bandwidth is in the range of 11.29–17.32 GHz. This MoO2-modified carbon material could serve as an EMA platform in the electromagnetic wave absorption fields.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"14 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143443912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Harvesting wideband and random vibration energy in the vehicle environment is a promising route to power mobile electronic devices. Conventional energy harvesters cannot realize steady-state output, making the energy management circuit design difficult. This work presents an electromagnetic harvester with a counterweight unit, a gearbox, and a generator, which can be adapted to wideband automatic energy storage and quantized output release. The counterweight unit with the low-frequency response can effectively sense the weak vibration. The coil spring in the energy storage gear train is in particular used to store low-frequency random vibration energy in the environment and release the energy stored by the coil spring by switching the gear train. Finally, the coil spring drives the generating gear train to realize the steady-state output of mechanical energy to electrical energy. At a frequency of 2.5 Hz and an acceleration of 0.4 g, the average output power of the automatic energy storage and steady-state output release energy harvester (ASSR) by using a coil spring to first store energy and then quantize the output is 114.5 times higher than that of the method of continuous generating without using a coil spring. The ASSR's energy output can charge the lithium battery (3.7 V, 40 mAh) from 2.6 to 3.716 V during a 60 km ride at an average speed of 12.7 km/h while powering the mobile phones and Bluetooth devices continuously through the energy management circuit. The strategy shows the great potential of micro-energy harvester in various wideband random vibration environments for powering electronics.
{"title":"An automatic energy storage and release high-performance micro-harvester with steady-state output for low-frequency random energy harvesting","authors":"Xiaoguang Song, Zhiqiang Lan, Kunru Li, Shuo Qian, Bing Han, Ruoyang Zhang, Pengfei Wu, Xiaojuan Hou, Jian He, Xiujian Chou","doi":"10.1063/5.0250922","DOIUrl":"https://doi.org/10.1063/5.0250922","url":null,"abstract":"Harvesting wideband and random vibration energy in the vehicle environment is a promising route to power mobile electronic devices. Conventional energy harvesters cannot realize steady-state output, making the energy management circuit design difficult. This work presents an electromagnetic harvester with a counterweight unit, a gearbox, and a generator, which can be adapted to wideband automatic energy storage and quantized output release. The counterweight unit with the low-frequency response can effectively sense the weak vibration. The coil spring in the energy storage gear train is in particular used to store low-frequency random vibration energy in the environment and release the energy stored by the coil spring by switching the gear train. Finally, the coil spring drives the generating gear train to realize the steady-state output of mechanical energy to electrical energy. At a frequency of 2.5 Hz and an acceleration of 0.4 g, the average output power of the automatic energy storage and steady-state output release energy harvester (ASSR) by using a coil spring to first store energy and then quantize the output is 114.5 times higher than that of the method of continuous generating without using a coil spring. The ASSR's energy output can charge the lithium battery (3.7 V, 40 mAh) from 2.6 to 3.716 V during a 60 km ride at an average speed of 12.7 km/h while powering the mobile phones and Bluetooth devices continuously through the energy management circuit. The strategy shows the great potential of micro-energy harvester in various wideband random vibration environments for powering electronics.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"111 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143443929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Baoyin Xu, Yue Zhou, Yaqi She, Zhanhui Ding, Yongfeng Li, Bin Yao, Hong-an Ma, Hongdong Li, Yucheng Lan
Exploring superhard materials is of great significance in materials research. Ternary B-C-N superhard compounds exhibit a superior thermal stability to diamond, with hardness surpassing cubic boron nitride. However, synthesizing cubic B-C-N compounds is challenging, and few studies have been reported on their high-temperature oxidation resistance, impeding their potential applications. In this study, cubic B-C-N compounds (c-BCN) were synthesized using the high-pressure high-temperature synthesis method at 10 GPa and 1530 °C, half the reported pressure and one-quarter lower than the reported temperature. The thermal stability of the obtained c-BCN compound was examined. The results indicated that the air oxidation temperature of c-BCN was as high as 1200 °C, suitable for high-speed cutting of hardened steels. This study provided a production method of cubic B-C-N superhard compounds and extended their potential applications to milling/machining.
{"title":"High-pressure high-temperature synthesis of cubic B-C-N compounds with high thermal stability","authors":"Baoyin Xu, Yue Zhou, Yaqi She, Zhanhui Ding, Yongfeng Li, Bin Yao, Hong-an Ma, Hongdong Li, Yucheng Lan","doi":"10.1063/5.0250854","DOIUrl":"https://doi.org/10.1063/5.0250854","url":null,"abstract":"Exploring superhard materials is of great significance in materials research. Ternary B-C-N superhard compounds exhibit a superior thermal stability to diamond, with hardness surpassing cubic boron nitride. However, synthesizing cubic B-C-N compounds is challenging, and few studies have been reported on their high-temperature oxidation resistance, impeding their potential applications. In this study, cubic B-C-N compounds (c-BCN) were synthesized using the high-pressure high-temperature synthesis method at 10 GPa and 1530 °C, half the reported pressure and one-quarter lower than the reported temperature. The thermal stability of the obtained c-BCN compound was examined. The results indicated that the air oxidation temperature of c-BCN was as high as 1200 °C, suitable for high-speed cutting of hardened steels. This study provided a production method of cubic B-C-N superhard compounds and extended their potential applications to milling/machining.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"81 4 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143443908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, thermal interface materials (TIMs) have garnered increasing attention in the field of thermal management for electronic devices. By effectively bridging the gap between electronic components and heat sinks, these materials significantly enhance heat transfer efficiency. This paper systematically reviews and analyzes the mechanisms, and the influencing factors associated with TIMs composed of graphene, carbon nanotubes, MXene, boron nitride compounds, and metal nanowires over recent years. Additionally, it delves into the challenges faced by these materials and explores its future research directions in thermal management. Future research endeavors are anticipated to focus on innovative designs for thermal conductivity networks in order to achieve further enhancements in the TIMs performance, ultimately paving the way for their practical application and commercialization.
{"title":"A perspective on mechanism of heat transfer and performance optimization in advanced thermal interface materials","authors":"Chen Liang, Jingtao Hong, Cheng Wan, Xinkai Ma, Zhiteng Wang, Xiuchen Zhao, Aijun Hou, Denis Nika, Yongjun Huo, Gang Zhang","doi":"10.1063/5.0250727","DOIUrl":"https://doi.org/10.1063/5.0250727","url":null,"abstract":"In recent years, thermal interface materials (TIMs) have garnered increasing attention in the field of thermal management for electronic devices. By effectively bridging the gap between electronic components and heat sinks, these materials significantly enhance heat transfer efficiency. This paper systematically reviews and analyzes the mechanisms, and the influencing factors associated with TIMs composed of graphene, carbon nanotubes, MXene, boron nitride compounds, and metal nanowires over recent years. Additionally, it delves into the challenges faced by these materials and explores its future research directions in thermal management. Future research endeavors are anticipated to focus on innovative designs for thermal conductivity networks in order to achieve further enhancements in the TIMs performance, ultimately paving the way for their practical application and commercialization.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"1 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143443931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Two monolithic edge-emitting passively mode-locked InAs/InGaAs semiconductor quantum dot lasers generating ps optical pulses at repetition rates of 10 GHz and optical frequency combs centered at 1260 nm are mutually coupled in an all-optical passive synchronization experiment. The two lasers, with different free-running repetition rates, are coupled through a long delay fiber path, they synchronize, and generate optical pulse trains with identical repetition rates in a wide range of experimental conditions (optical frequency, optical delay, and coupling strength). The common repetition rate can be easily fine-tuned with the control of the external coupling path length. In synchronized state, both lasers operate with significantly reduced timing jitter with respect to their free-running values. Finally, under specific conditions, the repetition rate locking is accompanied by partial mutual coherence between the lasers, as indicated by the formation of interferometric fringes.
{"title":"Experimental demonstration of synchronization between two quantum dot passively mode-locked laser frequency combs utilizing bidirectional optical coupling","authors":"Daniel Bita, Iraklis Simos, Christos Simos","doi":"10.1063/5.0246902","DOIUrl":"https://doi.org/10.1063/5.0246902","url":null,"abstract":"Two monolithic edge-emitting passively mode-locked InAs/InGaAs semiconductor quantum dot lasers generating ps optical pulses at repetition rates of 10 GHz and optical frequency combs centered at 1260 nm are mutually coupled in an all-optical passive synchronization experiment. The two lasers, with different free-running repetition rates, are coupled through a long delay fiber path, they synchronize, and generate optical pulse trains with identical repetition rates in a wide range of experimental conditions (optical frequency, optical delay, and coupling strength). The common repetition rate can be easily fine-tuned with the control of the external coupling path length. In synchronized state, both lasers operate with significantly reduced timing jitter with respect to their free-running values. Finally, under specific conditions, the repetition rate locking is accompanied by partial mutual coherence between the lasers, as indicated by the formation of interferometric fringes.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"58 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143443886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhao Pan, Sergey A. Nikolaev, Jie Zhang, Maocai Pi, Mengqi Ye, Qiumin Liu, Xubin Ye, Xiao Wang, Takumi Nishikubo, Shogo Kawaguchi, Masaki Azuma, Youwen Long
PbTiO3 is a typical perovskite-type ferroelectric that shows unique negative thermal expansion (NTE) from room temperature to its Curie temperature (α¯V = −1.99 × 10−5 K−1, 300–763 K). It is widely accepted that enhanced NTE can be achieved in PbTiO3-based ferroelectrics by improving the tetragonality of PbTiO3 (c/a = 1.064) through chemical substitutions. Nevertheless, most substituted PbTiO3-based ferroelectrics exhibit reduced tetragonality and weakened NTE, while enhanced NTE has only been achieved in those materials with enhanced tetragonality so far. Herein, we report on (1 − x)PbTiO3-xBiAlO3 solid solutions for which we observe reduced tetragonality accompanied by an unusual enhanced NTE (c/a = 1.057, α¯V = −2.23 × 10−5 K−1, 300–740 K), without much degradation of the NTE temperature range of pristine PbTiO3 upon doping. The present study provides an example of unusual enhanced NTE accompanied by reduced tetragonality in PbTiO3-based perovskites, which will extend the scope of NTE in PbTiO3-based ferroelectrics and shed light on the understanding of enhanced NTE in PbTiO3 family.
{"title":"Extend the scope of negative thermal expansion in PbTiO3-based perovskites","authors":"Zhao Pan, Sergey A. Nikolaev, Jie Zhang, Maocai Pi, Mengqi Ye, Qiumin Liu, Xubin Ye, Xiao Wang, Takumi Nishikubo, Shogo Kawaguchi, Masaki Azuma, Youwen Long","doi":"10.1063/5.0253686","DOIUrl":"https://doi.org/10.1063/5.0253686","url":null,"abstract":"PbTiO3 is a typical perovskite-type ferroelectric that shows unique negative thermal expansion (NTE) from room temperature to its Curie temperature (α¯V = −1.99 × 10−5 K−1, 300–763 K). It is widely accepted that enhanced NTE can be achieved in PbTiO3-based ferroelectrics by improving the tetragonality of PbTiO3 (c/a = 1.064) through chemical substitutions. Nevertheless, most substituted PbTiO3-based ferroelectrics exhibit reduced tetragonality and weakened NTE, while enhanced NTE has only been achieved in those materials with enhanced tetragonality so far. Herein, we report on (1 − x)PbTiO3-xBiAlO3 solid solutions for which we observe reduced tetragonality accompanied by an unusual enhanced NTE (c/a = 1.057, α¯V = −2.23 × 10−5 K−1, 300–740 K), without much degradation of the NTE temperature range of pristine PbTiO3 upon doping. The present study provides an example of unusual enhanced NTE accompanied by reduced tetragonality in PbTiO3-based perovskites, which will extend the scope of NTE in PbTiO3-based ferroelectrics and shed light on the understanding of enhanced NTE in PbTiO3 family.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"49 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143443910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Terahertz technology is poised to revolutionize next-generation wireless communication systems, such as 5G-A and 6G, by addressing the growing need for efficient electromagnetic wave modulation in the terahertz frequency band. In this study, we present a reflective metasurface comprising dual metal layers and a tunable liquid crystal medium, designed to achieve dynamic linear-to-circular polarization conversion. Experimental results demonstrate polarization conversion across three frequency bands: 248–254, 265–278, and 287–292 GHz. Furthermore, left-hand circular polarization (LHCP)-to-right-hand circular polarization (RHCP) switching is achieved at 248–254 and 287–292 GHz, with a stable RHCP state observed at 265–278 GHz. These findings validate the device's ability to dynamically control polarization states through applied bias voltage. By enabling precise and flexible modulation, this metasurface provides a scalable and efficient solution for reconfigurable intelligent surfaces, paving the way for advanced terahertz communication systems in future wireless networks.
{"title":"Tri-band terahertz polarization reconfigurable reflective metasurface based on liquid crystal","authors":"Qi Xie, Bao Zhang, Shui Liu, Jingxia Qiang, Yamei Zhang, Feng Xu","doi":"10.1063/5.0251461","DOIUrl":"https://doi.org/10.1063/5.0251461","url":null,"abstract":"Terahertz technology is poised to revolutionize next-generation wireless communication systems, such as 5G-A and 6G, by addressing the growing need for efficient electromagnetic wave modulation in the terahertz frequency band. In this study, we present a reflective metasurface comprising dual metal layers and a tunable liquid crystal medium, designed to achieve dynamic linear-to-circular polarization conversion. Experimental results demonstrate polarization conversion across three frequency bands: 248–254, 265–278, and 287–292 GHz. Furthermore, left-hand circular polarization (LHCP)-to-right-hand circular polarization (RHCP) switching is achieved at 248–254 and 287–292 GHz, with a stable RHCP state observed at 265–278 GHz. These findings validate the device's ability to dynamically control polarization states through applied bias voltage. By enabling precise and flexible modulation, this metasurface provides a scalable and efficient solution for reconfigurable intelligent surfaces, paving the way for advanced terahertz communication systems in future wireless networks.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"64 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143443888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this Letter, the Venturi effect is introduced to change the vibration behaviors of a downwind bluff body and a piezoelectric wind-induced vibration energy harvester using the Venturi effect (VE-PWVEH) is reported to offer an alternative solution to enable a high-performance downwind PWVEH. Also, the power generation characteristics were readily adjusted by the flow channel forming the Venturi effect without modifying the PWVEH structure. So, the VE-PWVEH could possess both great power-generating capability at low wind speed and strong robustness at high wind speed. The results demonstrated that both the output voltage and cut-in wind speed were affected by the attack angle of two rectangular plates used for stimulating the constricted channel. There was an optimal attack angle of 60° where a maximum peak voltage of the VE-PWVEH was increased by 621% and the cut-in wind speed was reduced by 171% compared with the harvester without the Venturi effect. Besides, it demonstrated the VE-PWVEH could achieve an output power of 0.863 mW and illuminate about 120 blue LEDs in series. The introduction of the Venturi effect provides a simple and viable method of flow field disturbance to tune the performance of PWVEHs.
{"title":"A piezoelectric wind-induced vibration energy harvester via the Venturi effect","authors":"Mengsong Zhu, Zhenli Kuang, Weilin Liao, Jinbo Zhang, Linfei Fu, Zhonghua Zhang, Junwu Kan","doi":"10.1063/5.0249187","DOIUrl":"https://doi.org/10.1063/5.0249187","url":null,"abstract":"In this Letter, the Venturi effect is introduced to change the vibration behaviors of a downwind bluff body and a piezoelectric wind-induced vibration energy harvester using the Venturi effect (VE-PWVEH) is reported to offer an alternative solution to enable a high-performance downwind PWVEH. Also, the power generation characteristics were readily adjusted by the flow channel forming the Venturi effect without modifying the PWVEH structure. So, the VE-PWVEH could possess both great power-generating capability at low wind speed and strong robustness at high wind speed. The results demonstrated that both the output voltage and cut-in wind speed were affected by the attack angle of two rectangular plates used for stimulating the constricted channel. There was an optimal attack angle of 60° where a maximum peak voltage of the VE-PWVEH was increased by 621% and the cut-in wind speed was reduced by 171% compared with the harvester without the Venturi effect. Besides, it demonstrated the VE-PWVEH could achieve an output power of 0.863 mW and illuminate about 120 blue LEDs in series. The introduction of the Venturi effect provides a simple and viable method of flow field disturbance to tune the performance of PWVEHs.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"36 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143443885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wearable thermoelectric generators (WTEGs) are of significance in the conversion of body heat into electricity for the purpose of powering wearable electronic devices. Two-dimensional (2D) transition metal dichalcogenides (TMDCs) exhibit exceptional thermoelectric power factors and mechanical stability, making them promising flexible thermoelectric materials. However, the output voltage of the present TMDC-based WTEGs remains at a relatively low level. In this study, we precisely modulate the electronic structure of titanium disulfide (TiS2) nanosheets in a restacked film by surface modification, leading to the decoupling phenomenon of a simultaneous rise in the electrical conductivity and the Seebeck coefficient. This method enhances the thermoelectric power factor by approximately 14 times compared to pre-modified samples. We fabricated a flexible self-reassembly WTEG using 1T-phase molybdenum disulfide (MoS2) nanosheets as p-type material and modified TiS2 nanosheets as an n-type material. The generator achieved a voltage output of approximately 15 mV while harvesting heat from the human arm, showcasing its potential for practical applications.
{"title":"Self-reassembly wearable thermoelectric generator using surface-modified TMDCs","authors":"Yaocheng Yang, Huihui Huang","doi":"10.1063/5.0244224","DOIUrl":"https://doi.org/10.1063/5.0244224","url":null,"abstract":"Wearable thermoelectric generators (WTEGs) are of significance in the conversion of body heat into electricity for the purpose of powering wearable electronic devices. Two-dimensional (2D) transition metal dichalcogenides (TMDCs) exhibit exceptional thermoelectric power factors and mechanical stability, making them promising flexible thermoelectric materials. However, the output voltage of the present TMDC-based WTEGs remains at a relatively low level. In this study, we precisely modulate the electronic structure of titanium disulfide (TiS2) nanosheets in a restacked film by surface modification, leading to the decoupling phenomenon of a simultaneous rise in the electrical conductivity and the Seebeck coefficient. This method enhances the thermoelectric power factor by approximately 14 times compared to pre-modified samples. We fabricated a flexible self-reassembly WTEG using 1T-phase molybdenum disulfide (MoS2) nanosheets as p-type material and modified TiS2 nanosheets as an n-type material. The generator achieved a voltage output of approximately 15 mV while harvesting heat from the human arm, showcasing its potential for practical applications.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"11 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143443909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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